Movement absorbing lower links hitch frame pivotally connected about an upwardly forwardly inclined axis to a reciprocating harrow

ABSTRACT

An agricultural implement is provided comprising a frame, to be connected to a tractor and a reciprocating tool cultivating the soil. For preventing the reciprocating tool to force the tractor to make an oscillatory movement the tractor is connected to the frame of the implement through an auxiliary frame which is connected swingably to the frame for a swinging movement around an axis inclining forwardly.

United States Patent Vissers 1 Dec. 19, 1972 [54] MOVEMENT ABSORBINGLOWER 2,888,997 6/1959 Fraga ..l72/449 3,520,372 7/1970 Beck LINKS HITCHFRAME PIVOTALLY 3,219,127 11/1965 Van Der Lely et al ..172/449 CONNECTEDABOUT AN UPWARDLY FORWARDLY INCLINED AXIS To A FOREIGN PATENTS ORAPPLICATIONS RECIPROCATING ARROW 1,501,335 11/1967 France ..172/4396,703,867 9/1968 Nether1ands.. ..i..l72/l()2 [72] Inventor g t N'euwvennep 84,701 4/1958 Denmark. .....172/447 ct er 5 1,132,375 5/1962Germany ..172/450 [73] Assignee: H. Vissers N.V., Nieu'w-Vennep,

Netherlands Primary Examiner-Robert E. Pulfrey Assistant Examiner-C. W.Hanor 1 Flledi P 8, 1970 AttorneySnyder and Butrum A l. N 70,054 [21] pp0 [57 ABSTRACT An agricultural implement is provided comprising a [30]Foreign Apphcatlon Pnomy Dat-a frame, to be connected to a tractor and areciprocat- Sept. 17, 1969 Netherlands ..69/14073 ing tool cultivatingthe soil.

' a For preventing the reciprocating tool to force the trac- [52]U.S.Cl. ....l72/102, 1-72/449, 172/678 tor to make an oscillatorymovement the tractor is [51] 1111- CL MAO, 35/10 Aolb 59/061 Aolb 61/02connected to the frame of the implement through an Field 9fSearch-172F101 541 auxiliary frame which is connected swingably to the 7/101-102, 439, 447, 449, 450, frame for a swinging movement around anaxis inclining forwardly. [56] References Cited 8 Claims, 3 DrawingFigures UNITED STATES PATENTS 2,872,990 2/1959 Fraga ..l72/449 PATENTEDDEC 1 9 I972 sum 1 or 2 FIG! INVENTOR MOVEMENT ABSORBING LOWER LINKSHITCH FRAME PIVOTALLY CONNECTED ABOUT AN UPWARDLY FORWARDLY INCLINE!)AXIS TO A RECIPROCATHNG HARROW The invention relates to an agriculturalimplement for cultivating soil, more particularly a harrow, saidimplement being adapted to be moved in a forward direction andcomprising a frame, a tool which is supported by said frame, drivingmeans for reciprocating said tool transversely of said forwarddirection, and comprising an auxiliary frame to be suspended from atractor, which auxiliary frame can swing in relation to the frame arounda standing axis extending in a central longitudinal plane of theimplement.

An agricultural implement of the kind specified is known. Thereciprocating tool tends to force the agricultural implement to make anoscillatory movement. In the prior art agricultural implement theoxcillatory movement is absorbed by springs disposed between theauxiliary frame and the frame. Despite the springs both the agriculturalimplement and the tractor are liable to violent jolting which isuncomfortable to the tractor driver and also causes heavy wear to thetractor and the agricultural implement.

These disadvantages are obviated according to the invention by forwardlyinclining said standing axis. If the agricultural implement is deflectedto one side, the tool penetrates more deeply into the soil on that side,so that the soil on that side of the agricultural implement exerts arearwardly-directed corrective extra force thereon to force theimplement back into the center. Such corrective force reduces therestoring force which the tractor must exert on the agriculturalimplement via springs disposed between the frame and the auxiliary frameto hold the agricultural implement steady.

A further development of the agricultural implement according to theinvention completely obviates the restoring force which the tractor mustexert on the agricultural implement. This agricultural implement ischaracterized by a free swinging movement around the standing axisbetween the frame and the auxiliary frame.

The springs between the auxiliary frame and the frame are thereforeeliminated, thus making the implement even cheaper. Another importantfeature is that the frame of the implement is substantially quieter andthe tractor does not experience jolting movements.

The invention will now be described in detail with reference to thedrawings, wherein:

H08. 1 and 2 are partly cutaway plan and side views respectively of aharrow according to the invention, and

FIG. 3 is a preferred variant of a detail of FIG. 1.

A harrow frame comprises a transverse beam 1, a transverse beam 2, twolongitudinal beams 3, a horizontal longitudinally extending bearing bush4, two inclined supports 5 connecting the bearing bush 4 to thelongitudinal beams 3, and two supporting plates 6 extending at aninclination upwardly from the longitudinal beams 3 and each having a lug7.

Lugs 8 for the pivotable mounting of levers 9 are disposed at the endsof the transverse beam 1. Ends 10 of the levers 9 are hingeablyconnected to harrow bars having tines 12. The harrow bars 11 aretherefore attached to the frame 1 with provision for lateralreciprocation and form the tool of the agricultural implement.

The reciprocating harrow bars 11 are driven from power take off 13 ofthe tractor which power take ofi is connected via a universal joint 14to drive-shaft 15.

The driveshaft 15 is mounted for rotation in the bush 4 and terminatesin a flange 16 to which a flywheel 17 is attached. The flange 16 has twolugs 18 to which a bush 19 is attached to hinge around a holt 20extending through such lugs. The free stem end 21 of a fork 22 ispivotably mounted in the bush 19. The fork 22 engages via ball bearings23 two coaxial transverse arms 24 of a crank 25. When the shaft 15rotates, the crank 25 makes an oscillatory movement. The crank 25 has atits bottom end two arms 26 which are offset by an angle of in relationto the transverse arms 24. The ends of the crank arms 26 have bearingbushes 27 for vertical pins 28 disposed on the top of the harrow bars 1l.

The harrow is attached to a tractor (not shown) by means of two levers29 which are connected to the tractor by their front ends at the sameheight via universal joints and can be adjusted to the required angleand retained therein by a lifting device, to enable the height of theimplement to be adjusted in relation to the tractor. A third suspensionmember used is a top bar 30 also connected by its front end to thetractor via a universal joint. The rear end of the bar 30 is connectedvia a ball and socket joint 31 to a pin 32 extending through the lugs 7.The rear ends of the levers 29 are each hingeably attached via a balland socket joint 33 to a pin 34 extending through lugs 36 of atransverse bar 35 which forms the auxiliary frame and is connected via apivot pin 37 to the transverse member 2 of the frame. The pivot pin 37is coaxial with a forwardly inclined standing axis 40 extending in thecentral longitudinal plane. The angle b enclosed with the vertical is,for instance, 5.

With the described construction of the connection between the tractorand the harrow, the harrow frame can make oscillatory swinging movementsin relation to the auxiliary frame 35 and the tractor around thestanding axis 40.

When during an oscillatory movement the harrow is deflected, forinstance, to the right, due to the forwardly inclined axis 40 the toolconsisting of the harrow bars 11 penetrates somewhat more deeply intothe soil on the right-hand side, whereas on the left-hand side thedevice is raised somewhat, so that the normal soil cultivating force K,is corrected by opposite corrective forces K together forming arestoring torque forcing the harrow back into its starting position.Such restoring torque reduces the restoring torque exerted by springs 39and therefore reduces tractor jolting.

Preferably, as shown in FIG. 3, the springs 39 are omitted. At each pin38, a clearance a is left between the frame and the auxiliary frame 35.During tests with a particular harrow, a clearance a of the order of 5cm was found to be completely adequate to prevent the frame and theauxiliary frame 35 from repeatedly knocking together and causing ajolting effect.

What i claim is:

1. An agricultural implement adapted to be secured to a tractor having apower take-off, transversely spaced lower lift links and a central upperlink, said implement comprising:

an auxiliary frame including means pivotally connecting the auxiliaryframe to said lower lift links about a horizontal transverse axis;

, an implement frame including means pivotally connecting the implementframe to said upper link; coupling means pivotally connecting saidimplement frame to said auxiliary frame about a pivot axis lying in avertical longitudinal plane and inclined upwardly forwardly therewithin;

guide means connecting said implement frame to said auxiliary frame atlaterally spaced points on opposite sides of said coupling means forallowing limited relative motion between said frames about said pivotaxis;

a cultivating implementincluding means mounting the cultivatingimplement on said implement frame for transverse reciprocation withrespect thereto; and

drive means connecting said power take-off to said implement foreffecting said reciprocation of the implement.

2. An agricultural implement as defined in claim 1 including springmeans interposed between said auxiliary and implement frames forresisting pivotal motion therebetween about said pivot axis.

3. An agricultural implement as defined in claim 1 wherein said drivemeans includes a longitudinally extending shaft carried by saidimplement frame and a universal joint on said shaft located along anextension of said pivot axis. I

4. An agricultural implement as defined in claim 3 wherein the pivotalconnections between said lower links and said auxiliary frame and thepivotal connection between said implement frame and the upper link lieforwardly of said pivot axis.

5. An agricultural implement as defined in claim 1 wherein said guidemeans comprises a pair of rearwardly projecting pins fixed to saidauxiliary frame and forwardly projecting tubular frame portions on saidimplement frame receiving said pins.

6. An agricultural implement as defined in claim 5 including springmeans interposed between said auxiliary and implement frames forresisting pivotal motion therebetween about said pivot axis.

7. An agricultural implement as defined'in claim 5 wherein said drivemeans includes a longitudinally extending shaft carried by saidimplement frame and a universal joint on said shaft located along anextension of said pivot axis.

8. An agricultural implement as defined in claim 7 wherein the pivotalconnections between said lower links and said auxiliary frame and thepivotal connection between said implement frame and the upper link lieforwardly of said pivot axis.

1. An agricultural implement adapted to be secured to a tractor having apower take-off, transversely spaced lower lift links and a central upperlink, said implement comprising: an auxiliary frame including meanspivotally connecting the auxiliary frame to said lower lift links abouta horizontal transverse axis; an implement frame including meanspivotally connecting the implement frame to said upper link; couplingmeans piVotally connecting said implement frame to said auxiliary frameabout a pivot axis lying in a vertical longitudinal plane and inclinedupwardly forwardly therewithin; guide means connecting said implementframe to said auxiliary frame at laterally spaced points on oppositesides of said coupling means for allowing limited relative motionbetween said frames about said pivot axis; a cultivating implementincluding means mounting the cultivating implement on said implementframe for transverse reciprocation with respect thereto; and drive meansconnecting said power take-off to said implement for effecting saidreciprocation of the implement.
 2. An agricultural implement as definedin claim 1 including spring means interposed between said auxiliary andimplement frames for resisting pivotal motion therebetween about saidpivot axis.
 3. An agricultural implement as defined in claim 1 whereinsaid drive means includes a longitudinally extending shaft carried bysaid implement frame and a universal joint on said shaft located alongan extension of said pivot axis.
 4. An agricultural implement as definedin claim 3 wherein the pivotal connections between said lower links andsaid auxiliary frame and the pivotal connection between said implementframe and the upper link lie forwardly of said pivot axis.
 5. Anagricultural implement as defined in claim 1 wherein said guide meanscomprises a pair of rearwardly projecting pins fixed to said auxiliaryframe and forwardly projecting tubular frame portions on said implementframe receiving said pins.
 6. An agricultural implement as defined inclaim 5 including spring means interposed between said auxiliary andimplement frames for resisting pivotal motion therebetween about saidpivot axis.
 7. An agricultural implement as defined in claim 5 whereinsaid drive means includes a longitudinally extending shaft carried bysaid implement frame and a universal joint on said shaft located alongan extension of said pivot axis.
 8. An agricultural implement as definedin claim 7 wherein the pivotal connections between said lower links andsaid auxiliary frame and the pivotal connection between said implementframe and the upper link lie forwardly of said pivot axis.